```
Exception in thread "main" java.lang.NumberFormatException: For input string: "9999999999999999999"
	at java.lang.NumberFormatException.forInputString(NumberFormatException.java:65)
	at java.lang.Integer.parseInt(Integer.java:495)
	at ru.fizteh.fivt.students.eltyshev.calc.ExpressionSolver.makeNumber(ExpressionSolver.java:140)
	at ru.fizteh.fivt.students.eltyshev.calc.ExpressionSolver.executeTree(ExpressionSolver.java:131)
	at ru.fizteh.fivt.students.eltyshev.calc.ExpressionSolver.calculate(ExpressionSolver.java:116)
	at ru.fizteh.fivt.students.eltyshev.calc.ExpressionSolver.execute(ExpressionSolver.java:18)
	at ru.fizteh.fivt.students.eltyshev.calc.Program.main(Program.java:21)
```